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Abstract-A novel approach to utilising digital computers and a collection of reference data for the interpretation of T N M R spectra is outlined. Because of the almost unlimited possibilities of molecular structures in organic chemistry, a matching of subspectra with substructures seems most appropriate, followed by an iterative confirmation of the suggested structures. For this purpose the possibility of a search for structure increments and the accompanying chemical shifts is provided by linking the spectroscopic and structural information using a formulae reading machine and generating the topological connectivity table. Three practical examples demonstrate the application of this set of programs and some of the experiences gained during operation.MANY attempts have been made recently to make use of the potential of digital computers in aiialytical chemistry, both for automation of spectrometers and for computer aided interpretation of the spectra obtained. It is self-evident that very few of these approaches are original in the basic idea; it seems essential, however, to try to find new combinations of the potential search strategies fitting to the specific needs of individual spectroscopic techniques and laboratories. Our concept for the interpretation of analytical data and the elucidation of molecular structures is based on the seven following assumptions.(1) Y N M R spectro~copyl-~ is ideally suited for this kind of work, because the proton-noise decoupled spectra display single, well separated lines, one for each carbon nucleus in the molecule. The spectral parameters (chemical shift and multiplicity) are characteristic for each compound; however structural changes further away in the molecule affect the chemical shifts only to a rather small degree.(2) Despite the decreasing cost of computer time and the rising salaries of skilled technicians (for spectroscopy), setting up a computer system with programs and especially a large data collection is still very expensive, and we can only expect a return on this investment when we succeed in identifying large difficult structures which are not otherwise accessible. On the other hand, when the interpretation system is available it should also be used extensively for minor problems; this is guaranteed by interactive programs with a time share systems and terminals near the spectroscopist's desk.(3) Due to the variability of organic structures it is highly improbable that an identical compound will be found in any collection of spectroscopic data-even one with 100,000 and more references. This is especially important for laboratories where novel compounds of unknown structure are synthesised. Thus the aim of any search strategy should not be to find identities, but similarities, and especially similarities of parts of the molecule (substructures).(4) Parts of large molecules are more representative than small molecules for similar parts of other large molecules, because steric and solvent interactions vary considerably. Thus the search strategy should be direct...

Mit Hilfe von Durchsicht‐ und Reflexionsspektren werden die Farberscheinungen an monodispersen Latices als Bragg‐Reflexe mit sichtbarem Licht identifiziert. Durch eine vollständige Strukturanalyse wird gezeigt, daß die kugligen Teilchen derartiger Dispersionen mit Durchmessern von 0,1 μ bis 1 μ bei genügender Konzentration in der kubisch dichtesten Kugelpackung kristallisieren. Neben aufschlußreichen kolloidchemischen Hinweisen geben derartige Latices eine interessante optische Parallele zu den Röntgenstruktur‐untersuchungen.

V o i i den i n der voraiigeheiideii A r k i t ' ) nuf indirektem Weae iiachgewicsc.lcn Brags-Keflcxcii wcrdcn eiiiige Linter Benutzung cines Lichtctreugerstes direkt zcrncsscii.Sonic o i tlic l3ragg refexc.; \\;hich wwc identified indirectly in the preceding papcr arc ineasurcd dircctly by using a light Fcattering apparatus.

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